External Costs of Agricultural Production in the United States 61Category 1 summary
Total damage to water resources due to agricultural production, according to avail-
able research, is calculated to be $419.4 million per year. Crop or livestock produc-
tion is associated with these costs as follows:
- Livestock – treatment for microbial pathogens ($118.6 million);
- Crop – infrastructure needs for treatment of nitrate and pesticides ($300.8
million).
Using the above cost totals and 168.8 million hectares of cropland, water resources
are impacted by cropland at a level of $1.78 per hectare annually.
This is not a complete review of all impacts on water by agricultural produc-
tion. Of note, the multifaceted impacts of agricultural chemicals and sedimenta-
tion on aquatic ecosystems are not included here. The next subsection on soil
resources addresses effects of sedimentation on water treatment, storage and con-
veyance systems. Valuation also is included for fish kills due to pesticides in Sub-
section 4. However, these do not fully address structural disturbances to habitats
and the food chain of aquatic environments.
(2) Damage to soil resources
Agriculture practices result in soil erosion through tillage, cultivation and land left
bare after harvest. After such disturbances, wind and water carry soil particles off
the land. In 1997, average annual soil erosion due to water from cropland and land
in the Conservation Reserve Program (CRP) was 969 million tonnes, with approx-
imately 958 million tonnes coming off cropland. Erosion due to wind in that same
year was 762 million tonnes (USDA, 2000c). Conservation efforts since 1982
have reduced soil erosion by 38 per cent on cropland and CRP land combined
(USDA, 2001b), with the composition of the combined land use changing as cro-
pland has been enrolled in the CRP. Still, agriculture remains the single largest
contributor to soil erosion. To date, external costs of waterborne erosion have been
studied and quantified more than those of windborne erosion. Thus, the costs that
follow reflect damages due to waterborne erosion only. Because soil erosion greatly
affects the condition and use of surface waters, the following costs support the
need for integrated land and water policies.
Erosion reduces soil fertility, organic matter and water-holding capacity and
negatively affects productivity. Environmental externalities may result with
increases of fertilizer and pesticide use to counteract these effects. On-farm costs of
lost productivity due to soil erosion are not included here, assuming the majority
of these costs are borne by the producer. Although this is not entirely true, it is
beyond the scope of this study to identify on-site effects that have off-site impacts.
Some estimates of annual on-farm costs due to soil loss include $500–600 million
(Crosson, 1986), $500 million to $1.2 billion (Colacicco et al, 1989) and $27 bil-
lion (Pimentel et al, 1995).